Z8F0113HJ005EG Datasheet, PDF (36/245 Pages) Zilog, Inc. – High-Performance 8-Bit Microcontrollers

Z8 Encore! XP^® F0823 Series
Product Specification
21
Reset and Stop Mode Recovery
The Reset Controller within the Z8 Encore! XP F0823 Series controls Reset and Stop
Mode Recovery operation and provides indication of low supply voltage conditions. In
typical operation, the following events cause a Reset:
• Power-On Reset (POR)
• Voltage Brown-Out (VBO)
• Watchdog Timer time-out (when configured by the WDT_RES Flash Option Bit to
initiate a reset)
• External RESET pin assertion (when the alternate RESET function is enabled by the
GPIO register)
• On-chip Debugger initiated Reset (OCDCTL[0] set to 1)
When the device is in STOP Mode, a Stop Mode Recovery is initiated by either of the fol-
lowing:
• Watchdog Timer time-out
• GPIO port input pin transition on an enabled Stop Mode Recovery source
The VBO circuitry on the device performs the following function:
• Generates the VBO reset when the supply voltage drops below a minimum safe level
Reset Types
F0823 Series MCUs provide several different types of Reset operations. Stop Mode
Recovery is considered a form of Reset. Table 9 lists the types of Reset and their operating
characteristics. The duration of a System Reset is longer if the external crystal oscillator is
enabled by the Flash option bits; this configuration allows additional time for oscillator
startup.
Table 9. Reset and Stop Mode Recovery Characteristics and Latency
Reset Characteristics and Latency
Reset Type Control Registers
eZ8 CPU Reset Latency (Delay)
System Reset Reset (as applicable)
Reset 66 Internal Precision Oscillator Cycles
Stop Mode
Recovery
Unaffected, except WDT_CTL
and OSC_CTL registers
Reset 66 Internal Precision Oscillator Cycles
+ IPO startup time
PS024315-1011
PRELIMINARY
Reset and Stop Mode Recovery